Metallurgical vessel

ABSTRACT

There is disclosed a metallurgical vessel, such as a steelworks converter, having a refractory brick lining and a probe opening passing a wall of the vessel for introducing a measuring and/or sampling probe. In order that the probe opening will get obstructed only minimally, if at all, and possible deposits of slag will be removed easily and quickly, the probe opening is provided with a lining of graphite or a graphite/alumina mixture.

This application is a division of 07/595,587 field Oct. 11, 1990, nowU.S. Pat. NO. 5,096,165.

This invention relates to a metallurgical vessel, in particular asteelworks converter, comprising a refractory brick lining and a probeopening passing a wall of the vessel for introducing a measuring and/orsampling probe.

BACKGROUND OF THE INVENTION

A converter of this kind is known from EP-B-0 079 290. The probe openingis to enable the rapid introduction of a probe for the purpose of takinga sample or for the purpose of temperature measurement or any otherparameter measurement. A separate opening for the probe is suitable, inparticular, if the mouth of the converter is difficult to accede.

The refractory brick lining of a steelworks converter, as a rule,consists of magnesite bricks such that the probe opening passing throughthe wall of the converter has an internal wall formed by such magnesitebricks. In practice, it has proved that probe openings of this type growtogether or close up every now and then, because of slag depositsthereon which form particularly stable compounds with the magnesitebricks. Such deposits can be removed by boring the probe opening, yetthis frequently involves damage to the brick lining of the metallurgicalvessel and also requires much time. Since, however, measurements are tobe carried out as quickly as possible, the difficulty feasible cleaningof the probe opening prior to carrying out any measurement isparticularly disadvantageous.

OBJECT OF THE INVENTION

The invention aims at avoiding these disadvantages and difficulties andhas as its object to provide a metallurgical vessel of the initiallydefined kind, whose probe opening is obstructed only minimally, if atall, possible deposits of slag being easily and quickly removable.

SUMMARY OF THE INVENTION

In accordance with the invention, this object is achieved in that theprobe opening is provided with a lining of graphite or of agraphite/alumina mixture.

It has proved that slag adheres to graphite only with difficulty andthat possible slag deposits can readily be removed, e.g., by a handscraper.

Suitably, the inner end of the lining of the probe opening at leastreaches into a region of the fractory brick lining having a temperatureof about 1200° C. The slag used in the production of steel solidifiesbelow approximately 1200° C. such that the graphite or graphite/aluminamixture is to be provided in a manner projecting from the exterior to aregion having at least this temperature.

Advantageously, the inwardly projecting end of the lining of the probeopening maximally reaches into a region of the refractory brick lininghaving a temperature of about 1300° C. Since the slag is liquid aboveapproximately 1200° C., the slag automatically will flow off the bricklining in regions of the refractory brick lining in which temperatureslying above these values are attained such that magnesite bricks will doin these regions. In order to save material and to avoidhigh-temperature stresses on the graphite or graphite/alumina mixture,the lining according to the invention should not extend too far into theinterior of the vessel.

According to a preferred embodiment, the lining is designated as a pipe,thus rendering the installation especially simple.

In order to ensure a good fit of the pipe and hence a long service lifeof the same, the internal-side or inwardly extending and end of the pipeadvantageously is supported on a shoulder of a refractory lining brickof the metallurgical vessel.

In order to account for axial movements of the pipe, which aretemperature-dependent or due to movements of the brick lining material,without the pipe getting destroyed, the external-slide or the outwardlyextending end of the pipe advantageously is supported relative to theshell of the metallurgical vessel by means of a refractory ramming mass.The probe opening preferably extends outwardly through a socketconnected to the outer shell of the metallurgical vessel.

Since graphite usually reacts with oxygen and oxygen is present inexcess at a steelworks converter during the blowing procedure, the probeopening suitably is closable by a lid at the end of socket. In this way,the access of air from outside and the penetration of oxygen from insidethrough the probe opening a swell as adverse effects on the graphitelining caused thereby are prevented. In addition, the lid has theadvantage of preventing flames and flue gases from getting outsidethrough the probe opening.

Suitably, the lid is pivotably fastened to the shell of themetallurgical vessel, for example, at the end of the socket the lidadvantageously being actuatable by means of a pressure medium cylinder.

In order to ensure the closure of the lid during pivotal movements ofthe converter, the lid suitably is fixable by means of a locking device,which, suitably, is actuatable also by a pressure medium cylinder.

A preferred embodiment is characterized in that the pipe extendsapproximately over the entire length of the probe opening as far as tothe interior of the metallurgical vessel and is assembled of two or morepipe sections, whose ends facing each other are provided with front anend surfaces at least partially overlapping each other in end to endcontact in the direction transverse to the longitudinal axis. Theconfiguration of the pipe in several sections allows for movements ofthe brick lining material transverse to the axis of the probe openingwithout causing a rupture of the pipe and a lateral offset of the partsresulting from rupture. Such a lateral offset of a pipe section impairsthe introduction of the probe through the probe opening.

With the preferred embodiment of the pipe described above, displacementsof the brick lining materials, such as of the working lining--whosedisplacements are the largest at the internal wall of the vessel--merelycause a pivotal movement of a pipe section relative to the consecutivepipe section, which results in a slight buckling of the axis; yet, onepipe section is reliably prevented from getting offset relative tot heother, which would create a step within the probe opening impeding theentering movement of the probe.

Due to the pipe reaching as far as to the interior of the metallurgicalvessel, the possible deposition of slag at the transition from graphiteto magnesite bricks, which would have to be removed prior to introducinga probe, is prevented.

A particularly suitable embodiment is characterized in that the front orend faces are designed as envelope of cone areas whose generatricesenclose an angle of between 30° and 60°, preferably of 45°, with thelongitudinal axis. In other words, the ends are conically bevelled, oneend being a female bevel which mates with a male bevel of the other end.

In this case, the envelope of cone areas of two facing end parts of thepipe sections have equal angles of aperture, the tips of the conesforming the envelope of cone areas being directed towards the interiorof the metallurgical vessel. Thereby, a high degree of mobility of thepipe sections relative to one another is ensured and a gap possiblyforming between the pipe sections will not impair the introduction of aprobe due to the inclination of the gap in the direction towards theinterior of the metallurgical vessel.

In order to perfectly support and anchor the pipe sections in therefractory lining of the metallurgical vessel, the pipe section locatednext to the internal space of the metallurgical vessel advantageously isprovided with an annular bead or flange on its external side, whichforms a supporting shoulder.

Preferably, the pipe sections have cylindrical internal spaces, theinternal diameter of a pipe section arranged nearer to the interior ofthe metallurgical vessel being dimensioned larger than the internaldiameter of a pipe section located further outwards towards the socket,thus rendering a slight offset of a pipe section, or a change in theinclination of a pipe section, with respect to the adjacent pipe sectionirrelevant to introducing the probe.

Suitably, the difference between the internal diameters of one pipesection and the consecutive or coaxially extending pipe section rangesbetween 1 and 3 cm, preferably amounts to about 2 cm.

According to a further embodiment of the invention, the probe openingwill be kept free of slag by providing a stopper of graphite or agraphite/alumina mixture to be inserted into the probe opening and fixedin the inserted position.

Preferably, the inner stopper end at least projects into a region of therefractory brick lining that has a temperature of about 1200° C. and atmost projects into a region having a temperature of about 1300° C.

In order to enable the simple manipulation of the stopper, the latter isfastened to a guide rod, on which a stop is provided at a distance fromthe stopper, which contacts the outer shell of the metallurgical vessel.

In order to be able to adapt the position of the stopper to differentoperational conditions, the stop advantageously is displaceable alongthe guide rod and fixable to the guide rod.

Suitably, the stop is designed as a lid, thus preventing the penetrationof gas through the probe opening, which might occur on account of theplay provided between the stopper and the probe opening.

In order to ensure the simple installation of the lid, the stopadvantageously is provided with a centering projection on its sidefacing the interior of the metallurgical vessel.

For tiltable metallurgical vessels, the stop suitably is fixable to theshell of the metallurgical vessel by a locking device preferablyactuatable by a pressure medium cylinder.

Advantageously, the guide rod is actuatable by means of a pressuremedium cylinder such that no manipulations are required to lift andlower the stopper.

A preferred embodiment comprising a stopper is characterized in that thestopper extends over the entire length of the probe opening, its endfacing the internal side of the metallurgical vessel suitably having afront face matching this internal side of the vessel.

By providing a stopper extending as far as to the internal side of themetallurgical vessel, the penetration of slag into the probe opening anda possible deposit of slag on the refractory lining of the probe openingare reliably prevented.

A stopper of this type offers particular advantages if the probe hole isto remain closed for an extended period of time. A stopper of refractorymaterial would hardly be removable due to slag deposits forming betweenthe stopper and the brick lining; brick lining material would break off,which, however, is prevented by the graphite stopper.

Advantageously, the outwardly projecting end of the stopper at thesocket end is provided with a metal insert comprising a coupling meansfor coupling a stopper manipulation means thereto. The coupling means,for instance, may be designed as a bore having an internal thread intowhich thread a manipulation rod may be screwed.

Suitably, the metal insert comprises an annular bead overlapping theprobe opening. This annular bead forms kind of a lid such that even thethin gap between the stopper and the probe opening is covered towardsoutside. At the same time, this bead or frange serves as a support forthe stopper such that the latter will assume its correct position withinthe probe opening.

Preferably, the external diameter of the stopper is dimensioned to besmaller than the internal diameter of the probe opening by about 3 to15%, in particular 5%.

According to a preferred embodiment in case a pipe of a graphite/aluminamixture is used, the latter is comprised of 60 to 85% graphite, thebalance being Al₂ O₃ and fireclay.

When using a stopper of a graphite/alumina mixture, it is comprised of 5to 20% graphite, 30 to 70% Al₂ O₂, the balance being fireclay.

The invention is based on the idea of providing graphite or agraphite/alumina mixture in the region of the probe opening in whichslag is likely to deposit. In the case of a pipe-shaped graphite lining,the graphite region extends from a region of the brick lining in whichthe slag is sure to be liquid as far as to near the external-side end ofthe probe opening, if a stopper is provided, it suffices to make theinternal stopper end, which reaches as far as into the above-mentionedregion, of graphite or a graphite/alumina mixture.

With both variants, the refractory brick lining of the metallurgicalvessel is worn as has hitherto been the case, yet without loosing itsfunction to protect against slag deposits.

In the following, the invention will be explained in more detail by wayof several exemplary embodiments and with reference to the accompanyingdrawings, wherein:

THE DRAWINGS

FIG. 1 is a partial section through a steelworks converter, whose planeof section is laid through the axis of rotation of the steelworksconverter, according to a first embodiment;

FIG. 2 is a top view of FIG. 1 in the direction of arrow II:

FIGS. 3, 4 and 5 depict further embodiments in illustrations analogousto FIG. 1.

DETAILS OF THE INVENTION

According to the embodiment illustrated in FIG. 1, a probe opening 1 forintroducing and removing a measuring and/or sampling probe passes thewalls 2 of a metallurgical vessel 3, such as a steelworks converter,near its mouth 4. The wall 2 of the steelworks converter 3 is formed bya shell 5 of steel, on whose internal side a permanent lining 6 isprovided. The permanent lining 6 is covered by a refractory workinglining 7. In the region of the probe opening 1, the working lining 7 isformed by two bricks 9, 10 through which bore 8 extends and havingdimensions larger than those of the neighboring lining bricks 11 of theworking lining 7. All the bricks 9, 10, 11 of the working lining 7 aremade of magnesite having the following composition:

MgO : 97%

Al₂ O₃ : 0.1%

Fe₂ O₃ : 0.2%

CaO : 1.9%

SiO₂ : 0.5%

In the region of the probe opening 1, a socket 12 of steel having aflange-like front plate 13 is welded to the shell 2 of the converter 3.A pipe 14 of graphite is arranged within said socket, the internal space15 of the pipe being in alignment with the bore 8 passing through thetwo lining bricks 9, 10 of larger dimensions. The graphite pipe 14 issupported, by its inwardly projecting end 16, on a shoulder 17 of theupper 9 of the two lining bricks 9, 10 and is peripherally surrounded bya refractory ramming mass 18 filling the annular space between the shellof the socket 12 and the pipe 14. This ramming mass 18 also extends toor occupies the space between the external-side or outwardly extendingend 19 of the pipe 14 and the front plate 13 of the socket 12. Thus, thepipe is capable of performing axial displacements that aretemperature-dependent or caused by movements of the refractory bricklining 7, without being exposed to excessive pressure forces that mightresult in the destruction of the pipe 14. A central opening 20 in thefront plate registers with the internal space 15 of the pipe 14.

The graphite pipe 14 has an external diameter corresponding toapproximately twice the internal diameter, thus exhibiting asufficiently large stability. The graphite pipe 14 need not be designedin one piece, but may also be comprised of several graphite ringssuperposed in the axial direction.

To the front plate 13 of the socket 12, a lid 21 is pivotably fastened.The lid is designed like a pot, its interior being lined with arefractory mass 22 and facing the interior of the converter. On the lid21, there is provided a lateral projection 23 or lever allowing for themanual pivoting of the lid 21. This projection 23 may be overlapped by alocking device 24 attached to the front plate 13 of the socket 12likewisely in a pivotable manner such that the lid 21 is fixable in itsclosed position. Pressure-medium cylinders also might be provided topivot the lid 21 and the blocking means 24.

As is apparent, in particular from FIG. 1, the internal or inwardlyprojecting end 16 of the graphite pipe 14 is located at a distance 25from the internal wall 26 of the converter formed by the working lining7, which distance approximately corresponds to the thickness 27 of theworking lining 7 of a newly lined converter 3 such that the graphitepipe 14 still is well supported at the end of a converter campaign whenthe working lining 7 has been burnt off almost completely. Thetemperature of the brick lining, in the region of the internal orinwardly projecting end 16 of the graphite pipe 14, ranges between about1200° and 1300° C. such that slag penetrating into the bore 8 of the twoperforated lining bricks 9, 10 cannot adhere to the lining bricks 9, 10on account of the molten state of the slag in this temperature range,but flows off the same. The slag cannot deposit on the graphite pipe 14,either, whose temperature lies below the melting point of the slag. Slagpossibly solidifying in the interior 15 of the pie 14 is readilyremovable by a hand scraper, hardly adhering to the pipe 14.

According to the embodiment illustrated in FIG. 3, the refractoryworking lining 7 of the converter is led as far as to the front plate 13of the socket 12 and is pierced to form of a probe opening 1. Accordingto this embodiment, the adherence of slag is prevented by a stopper 28of graphite. This stopper is fastened to the end of a guide rod 29. Theguide rod 29 serves to remove the stopper from the bore 8, or tointroduce it into the same, manually. For this purpose, the guide rod isprovided with handles 30. It is also possible to provide a pressuremedium cylinder for removing and inserting the stopper 28, instead ofmanual actuation.

A lid 31 is movably arranged on the guide rod 29 for closing the probeopening 1. It may be fixed on the guide rod 29 at various distances fromthe stopper by a split-pin 32 or an adjustment screw. The lid 31 isprovided with a projection 33 that maybe overlapped by a locking device24 similar to the locking device illustrating in FIGS. 1 and 2 such thatthe lid 31 is fixed on the front plate 13 of the socket 12. Thus, thestopper 28 is fixed in the interior 8 of the probe opening 1, keepingits place during pivoting of the converter.

The lid 31, thus, serves as a stop for the stopper 28 to maintain apredetermined position in the interior 8 of the probe opening 1. As isapparent from FIG. 3, the front face 34 of the stopper 28 is at adistance 25 from the internal wall 26, that corresponds approximately tothe thickness 27 of the working lining 7. Also in this case, thetemperature on the front face 34 of the stopper within the probe openingamounts to about 1200° to 1300° C. such that no adherence of slag willoccur. For the purpose of centering the guide rod 29, the lid 31comprises a centering projection 35 projecting into the interior 8 ofthe probe opening 1 and whose external diameter is dimensioned to beonly slightly larger than the internal diameter of the probe opening 1.

According to FIG. 4, a pipe 36 formed of graphite or a graphite/aluminamixture extends approximately over the entire length of the probeopening 1, reaching as far as to the internal space 37 of themetallurgical vessel 3. It is assembled of two sections 36', 36",however, for particularly long probe openings 1, it could also becomposed of more than two sections.

The front faces 38, 39 provided on the ends of the pipe sections 36',36" facing each other are designed as envelope of cone areas that is,conically bevelled, the pipe sections 36', 36", thus, being immobilizedrelative to each other in the direction transverse to the longitudinalaxis 40 of the probe opening 1. The angle 41 of the generatrix of anenvelope of cone area, or the angle of the conically shaped bevels withrespect to the longitudinal axis 40 of a pipe section 36', 36" suitablyranges between 30° and 60°. In tests, a bevel angle 41° of 45° hasproved particularly advantageous. If the angle 41 is too steep or tooflat, parts of a pipe section 36', 36" may break off.

If a shift of the working lining 7 relative to the permanent lining 6occurs--which shift is the largest on the side 42 facing the interior ofthe vessel the inner pie section 36", i.e., that pipe section 36" whichreaches as far as to the internal space 37 of the metallurgical vessel3, is moved relative to the outer pipe section 36' in a manner that anangular deviation of the axes of the pipe sections 36', 3641 results. Onthe other hand, displacement of the two pipe sections relative to eachother transverse to the longitudinal axis 40 is not possible, becausethe adjacent front faces or conically shaped bevels 38, 39 of the pipesections 36', 36" overlap or contact each other in male-femalerelationship in the direction transverse to the longitudinal axis 40,thus being supported on each other in this direction. Instead of theenvelops of cone areas 38, 39, any other shapes of front faces may beemployed, for instance, complementary spherical face, or a stepwiseconfiguration of the front faces are feasible the end faces beingmatable in a male-female relationship when one end face is contactedwith the other.

The pipe section 36' that lies next to the internal space of themetallurgical vessel 3, on its outwardly directed end, comprises anannular bead or flange 43 constituting a supporting shoulder 44, bywhich it is supported and retained on the refractory ramming mass 45surrounding this pipe section 36".

In order to prevent even the slight protusion of an edge of the pipesection 36∝ if this pipe section 36" were moved by a drift of theworking lining 7 relative to the permanent lining 6, the internaldiameter 46 of the pipe section 36" arranged closer to the interiorspace 37 of the metallurgical vessel 3 suitably is dimensioned to beslightly larger than the internal diameter 47 of the adjacent pipesection 36' following outwardly, as is illustrated in dot-and-dash linesin FIG. 4. Suitably, the diameter difference amounts to about 2 cm.

The axial longitudinal displacement of the pipe sections 36', 36" may beenabled by a suitable clearance 48 in the outwardly extending region ofthe external pipe section 36', as is likewisely illustrated indot-and-dash lines in FIG. 4. With the embodiment illustrated in FIG. 4,a lid 21 also may be provided, as is illustrated in FIG. 1.

According to the embodiment illustrated in FIG. 5, the probe opening 1is surrounded by refractory ramming mass 18, 45 over its entire length.A stopper 49 of graphite or of a graphite/alumina mixture is inserted inthe probe opening 1, extending over the entire length of the probeopening 1 and whose inward end 50 matches or coincides with the internalside 42 of the vessel such that the stopper 49 basically does not form aprojection on the internal side 42 of the metallurgical vessel 3.

On the outer end of the stopper 49 at the socket, a metal insert 51 isincorporated in the same, constituting an annular bead or flange 52 thatoverlaps the probe opening 1, thus maintaining the stopper 49 in itscorrect position by the annular bead or flange 52 abutting on the frontplate 13 of the socket 12. A bore 53 is coaxially formed into the insert51, having an internal thread 54 such that a manipulation device forremoving the stopper 49 from, and inserting it into, the probe opening 1is attachable thereto. The stopper 49 has a lateral play 55 relative tothe probe opening 1, which preferably amounts to about 2.5% of thediameter of the probe opening 1.

With the embodiment illustrated in FIG. 5, the probe opening 1 couldalso be lined with a graphite pipe, as is illustrated in FIGS. 1, 3 and4.

The pipe or the stopper may be made of pure graphite (degree of purity99.9%). However, it is also possible to use a graphite/alumina mixture,which consists of 5 to 20% graphite, 30 to 60% Al₂ O₃ the balance beingfireclay, in the case of the stopper 28, and of 60 to 85% graphite, thebalance being Al₂ O₃ and fireclay, in the case of the pipe.

What we claim is:
 1. In a metallurgical vessel comprised of an outershell lined on its interior wall with a refractory brick lining andadapted for melting metal,said vessel having a probe opening therein ofa length extending from the outer shell to the interior of said vesselfor introducing a measuring and/or sampling probe therein, said probeopening entering said vessel through said brick lining along itslongitudinal axis, the combination therewith of a probe opening stopperentering said probe opening and made of a material selected from thegroup consisting of graphite and a graphite/alumina mixture consistingessentially by weight of about 60% to 85% graphite, with the balanceessentially alumina and fireclay.
 2. A metallurgical vessel as set forthin claim 1, wherein said stopper has an internal-side end which reachesat least as far as into a region of said refractory brick lining havinga temperature of about 1200° C.
 3. A metallurgical vessel as set forthin claim 1, wherein said stopper has an internal-side end whichmaximally reaches as far as into a region of said refractory bricklining having a temperature of about 1300° C.
 4. A metallurgical vesselas set forth in claim 1, further comprising a guide rod fastened to saidstopper and a stop provided on said guide rod at a distance from saidstopper, said stop abutting on the shell of said metallurgical vessel.5. A metallurgical vessel as set forth in claim 4, wherein said stop isdesigned to be displaceable along said guide rod and fixable on saidguide rod.
 6. A metallurgical vessel as set forth in claim 4, whereinsaid stop is designed as a lid.
 7. A metallurgical vessel as set forthin claim 4, further comprising a centering projection provided on saidstop on its side facing said vessel internal space.
 8. A metallurgicalvessel as set forth in claim 4, further comprising a blocking means forfixing said stop on the shell of said metallurgical vessel.
 9. Ametallurgical vessel as set forth in claim 8, further comprising apressure medium cylinder for actuating said blocking means.
 10. Ametallurgical vessel as set forth in claim 4, further comprising apressure medium cylinder for actuating said guide rod.
 11. Ametallurgical vessel as set forth in claim 1, wherein said stopperextends over the entire length of said probe opening.
 12. Ametallurgical vessel as set forth in claim 11, wherein said stopper hasa stopper end facing the internal side of said vessel and having a frontface matching said internal side of said vessel.
 13. A metallurgicalvessel as set forth in claim 11, wherein said stopper has a stopper endreaching outwardly and including a metal insert, said metal inserthaving a coupling means adapted for attachment of a stopper manipulationmeans.
 14. A metallurgical vessel as set forth in claim 13, furthercomprising an annular bead provided on said metal insert in a manneroverlapping said probe opening.
 15. A metallurgical vessel as set forthin claim 11, wherein said stopper has an external diameter dimensionedto be smaller than said internal diameter of said probe opening by about3 to 15%.
 16. A metallurgical vessel as set forth in claim 11, whereinsaid stopper has an external diameter dimensioned to be smaller thansaid internal diameter of said probe opening by about 5%.